3,834 research outputs found
Melanoma mimicking malignant peripheral nerve sheath tumor with spread to the cerebellopontine angle: Utility of next-generation sequencing in diagnosis
Cutaneous spindle cell malignancy is associated with a broad differential diagnosis, particularly in the absence of a known primary melanocytic lesion. We present an unusually challenging patient who presented with clinical symptoms involving cranial nerves VII and VIII and a parotid-region mass, which was S100-positive while lacking in melanocytic pigment and markers. Over a year after resection of the parotid mass, both a cutaneous primary lentigo maligna melanoma and a metastatic CP angle melanoma were diagnosed in the same patient, prompting reconsideration of the diagnosis in the original parotid-region mass. Next-generation sequencing of a panel of cancer-associated genes demonstrated 19 identical, clinically significant mutations as well as a high tumor mutation burden in both the parotid-region and CP angle tumors, indicating a metastatic relationship between the two and a melanocytic identity of the parotid-region tumor
Vertical diversity patterns and biotic interactions of trap-nesting bees along a fragmentation gradient of small secondary rainforest remnants
International audienceAbstractSecondary rainforest remnants might contribute to biodiversity conservation and preservation of healthy interspecific interactions with ongoing fragmentation. We studied the vertical distribution of trap-nesting bees along a fragmentation gradient of secondary forest remnants in Costa Rica. Fragment size did not affect bee abundance, diversity, and parasitism and mortality rates. However, height and edge effects influenced bee communities. Bees were more abundant in the canopy and the understory compared to an intermediate height, and bee diversity was higher in the canopy. Tree location (forest edge, intermediate distance, forest center) did not affect abundance but did affect bee diversity since most species preferred the forest interior. The cuckoo bees Aglaomelissa duckei and Coelioxys sp. 1 only partly followed their hosts’ patterns, two Centris species. We conclude that an increasing amount of edge habitat will have negative consequences for bee communities and will reduce the conservation value of secondary forest fragments
Painting the ideal home: using art to express visions of technologically supported independent living for older people in North East England
This paper describes the investigation of the development of future technological products to support older people in everyday living through the agency of a community art group. Recent research has identified a number of challenges facing designers seeking to use traditional participatory design approaches to gather technology requirements data from older people. Here, a project is described that sought to get a group of older people to think creatively about their needs and desires for technological support through the medium of paint. The artistic expression technique described in this article allowed the identification of issues that had also been found by previous research that used a range of different techniques. This indicates that the approach shows promise, as it allows information to be gathered in an environment that is comfortable and familiar using methods already known by the participants and which they find enjoyable. It provides a complement (or possible alternative) to standard protocols and has the potential benefit of extracting even richer information as the primary task for participants is enjoyable in its own right and is not associated with an interrogative process. Furthermore, it is argued that some of the key risks of traditional approaches are lessened or removed by the naturalistic setting of this approach
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Systematics and host associations of Ormyrus species (Hymenoptera: Chalcidoidea)
The genus Ormyrus has a worldwide distribution and
comprises about sixty recognized species. The higher
taxonomic relationships of the genus are uncertain, as
evidenced by its placement in the families Ormyridae,
Pteromalidae, or Torymidae. Here, the genus is described
in detail and a preliminary catalog of the world species
is provided.
The Nearctic species of Ormyrus have never been
revised and the original descriptions are inadequate for
separating species. Fifteen species have been described
from the Nearctic, but two were previously synonymized.
After examining all type material and over 8000 additional
specimens, I consider nine species to be valid and
relegate five to junior synonymy. The nine recognized
species are redescribed. With the description of seven
new species, the genus now comprises sixteen Nearctic
species; a key is provided for separating these species.
Certain characters such as color and size were found to be
quite variable in some species. Surface sculpture, as
documented through the use of SEM, proved especially
useful in separating species.
Thirteen of the sixteen Nearctic species may be
associated exclusively with cynipid galls on oaks. Host
records from specimen labels are summarized in tables, one
of which includes an updated list of all Nearctic oak
cynipids. Twig galls harbor several oligophagous species
of Ormyrus, many leaf galls just a single polyphagous
species, and "apple" galls usually none. Other hosts of
Nearctic species include cynipid galls on Rosaceae and a
pteromalid gall on blueberry. In other parts of the
world, dipteran and chalcidoid galls may be important
hosts.
Distributional patterns of Nearctic Ormyrus species
are compared with those of host cynipids and oaks
Chronology of dune development in the White River Badlands, northern Great Plains, USA
Aeolian dune field chronologies provide important information on drought history on the Great Plains. The White River Badlands (WRB) dunes are located approximately 60 km north of the Nebraska Sand Hills (NSH), in the western section of the northern Great Plains. Clifftop dunes, sand sheets, and stabilized northwest-southeast trending parabolic dunes are found on upland mesas and buttes, locally called tables. The result of this study is a dune stabilization history determined from samples collected from stratigraphic exposures and dune crests. Thirty-seven OSL ages, from this and previous investigations, show three periods of dune activity: 1) ~21,000 years ago to 12,000 years ago (a), 2) ~9 to 6 ka, and 3) post-700 a. Stratigraphic exposures and low-relief dune forms preserve evidence of late Pleistocene and middle Holocene dune development, while high-relief dune crests preserve evidence of late Holocene dune development. Results of 12 OSL ages from the most recent dune activation event indicate that Medieval Climate Anomaly (MCA) droughts and Little Ice Age (LIA) droughts caused dune reactivation on the tables. Dune reactivation was accompanied by other drought-driven geomorphological responses in the WRB, including fluvial incision of the prairie and formation of sod tables. Regional significance of the MCA and LIA droughts is supported by similarities in the aeolian chronologies of the NSH at 700–600 a and some western Great Plains dune fields at 420–210 a. Aerial photographs of the WRB show little activity during the Dust Bowl droughts of the 1930s
EVALUACIÓN DE LA COMUNIDAD DE HORMIGAS EN UNA ZONA URBANA NEOTROPICAL CON DIFERENTES NIVELES DE PERTURBACIÓN
Traditionally, urban areas have been described as sites inhabited by a reduced number of animal species. However, the new spaces created represent a new niche that some species take advantage of. This work characterized the ant community in four different microhabitats in an urban area of Costa Rica. Bait sampling of ants revealed a total of 22 species, 20 of which are native species. Four adjacent areas were sampled: the interior of a building, two green areas, and an ecological reserve. Comparing these four areas, the two green areas showed the greatest similarity, while the building interior was the least similar. The results suggest that urban green areas can serve as reservoirs for native biodiversity.Tradicionalmente, las áreas urbanas han sido descritas como sitios habitados por un número reducido deespecies animales. Sin embargo, los nuevos espacios creados podrían representar un nuevo nicho que algunas especies podrían aprovechar. Se caracterizó la comunidad de hormigas en cuatro diferentes microambientes en un área urbana de Costa Rica. Muestreos con cebos para hormigas muestran un total de 22 especies, de las cuales 20 son especies nativas. Se muestrearon cuatro áreas adyacentes: el interior de un edificio, dos jardines y una reserva ecológica. La comparación entre estas áreas, arroja que los dos jardines presentan la mayor similitud, mientras el interior del edificio es el menos similar. Los resultados sugieren que las áreas verdes en zonas urbanas pueden funcionar como reservorios para especies nativas de hormigas y posiblemente de algunos otros grupos
An assesment of the ant community in a Neotropical urban area with different levels of disturbance
Traditionally, urban areas have been described as sites inhabited by a reduced number of animal species. However, the new spaces created represent a new niche that some species take advantage of. This work characterized the ant community in four different microhabitats in an urban area of Costa Rica. Bait sampling of ants revealed a total of 22 species, 20 of which are native species. Four adjacent areas were sampled: the interior of a building, two green areas, and an ecological reserve.
Comparing these four areas, the two green areas showed the greatest similarity, while the building interior was the least similar. The results suggest that urban green areas can serve as reservoirs for native biodiversity.
Tradicionalmente, las áreas urbanas han sido descritas como sitios habitados por un número reducido de especies animales. Sin embargo, los nuevos espacios creados
podrían representar un nuevo nicho que algunas especies podrían aprovechar. Se caracterizó la comunidad de hormigas en cuatro diferentes microambientes en un
área urbana de Costa Rica. Muestreos con cebos para hormigas muestran un total de 22 especies, de las cuales 20 son especies nativas. Se muestrearon cuatro áreas
adyacentes: el interior de un edificio, dos jardines y una reserva ecológica. La comparación entre estas áreas, arroja que los dos jardines presentan la mayor
similitud, mientras el interior del edificio es el menos similar. Los resultados sugieren que las áreas verdes en zonas urbanas pueden funcionar como reservorios
para especies nativas de hormigas y posiblemente de algunos otros grupos
Provenance and Paleogeography of the 25-17 Ma Rainbow Gardens Formation: Evidence for Tectonic Activity at Ca. 19 Ma and Internal Drainage rather than Throughgoing Paleorivers on the Southwestern Colorado Plateau
The paleogeographic evolution of the Lake Mead region of southern Nevada and northwest Arizona is crucial to understanding the geologic history of the U.S. Southwest, including the evolution of the Colorado Plateau and formation of the Grand Canyon. The ca. 25–17 Ma Rainbow Gardens Formation in the Lake Mead region, the informally named, roughly coeval Jean Conglomerate, and the ca. 24–19 Ma Buck and Doe Conglomerate southeast of Lake Mead hold the only stratigraphic evidence for the Cenozoic pre-extensional geology and paleogeography of this area. Building on prior work, we present new sedimentologic and stratigraphic data, including sandstone provenance and detrital zircon data, to create a more detailed paleogeographic picture of the Lake Mead, Grand Wash Trough, and Hualapai Plateau region from 25 to 18 Ma. These data confirm that sediment was sourced primarily from Paleozoic strata exposed in surrounding Sevier and Laramide uplifts and active volcanic fields to the north. In addition, a distinctive signal of coarse sediment derived from Proterozoic crystalline basement first appeared in the southwestern corner of the basin ca. 25 Ma at the beginning of Rainbow Gardens Formation deposition and then prograded north and east ca. 19 Ma across the southern half of the basin. Regional thermochronologic data suggest that Cretaceous deposits likely blanketed the Lake Mead region by the end of Sevier thrusting. Post-Laramide northward cliff retreat off the Kingman/Mogollon uplifts left a stepped erosion surface with progressively younger strata preserved northward, on which Rainbow Gardens Formation strata were deposited. Deposition of the Rainbow Gardens Formation in general and the 19 Ma progradational pulse in particular may reflect tectonic uplift events just prior to onset of rapid extension at 17 Ma, as supported by both thermochronology and sedimentary data. Data presented here negate the California and Arizona River hypotheses for an “old” Grand Canyon and also negate models wherein the Rainbow Gardens Formation was the depocenter for a 25–18 Ma Little Colorado paleoriver flowing west through East Kaibab paleocanyons. Instead, provenance and paleocurrent data suggest local to regional sources for deposition of the Rainbow Gardens Formation atop a stripped low-relief western Colorado Plateau surface and preclude any significant input from a regional throughgoing paleoriver entering the basin from the east or northeast
Effect of moisture on leaf litter decomposition and its contribution to soil respiration in a temperate forest
The degree to which increased soil respiration rates following wetting is caused by plant (autotrophic) versus microbial (heterotrophic) processes, is still largely uninvestigated. Incubation studies suggest microbial processes play a role but it remains unclear whether there is a stimulation of the microbial population as a whole or an increase in the importance of specific substrates that become available with wetting of the soil. We took advantage of an ongoing manipulation of leaf litter <sup>14</sup>C contents at the Oak Ridge Reservation, Oak Ridge, Tennessee, to (1) determine the degree to which an increase in soil respiration rates that accompanied wetting of litter and soil, following a short period of drought, could be explained by heterotrophic contributions; and (2) investigate the potential causes of increased heterotrophic respiration in incubated litter and 0–5 cm mineral soil. The contribution of leaf litter decomposition increased from 6 ± 3 mg C m<sup>−2</sup> hr<sup>−1</sup> during a transient drought, to 63 ± 18 mg C m<sup>−2</sup> hr<sup>−1</sup> immediately after water addition, corresponding to an increase in the contribution to soil respiration from 5 ± 2% to 37 ± 8%. The increased relative contribution was sufficient to explain all of the observed increase in soil respiration for this one wetting event in the late growing season. Temperature (13°C versus 25°C) and moisture (dry versus field capacity) conditions did not change the relative contributions of different decomposition substrates in incubations, suggesting that more slowly cycling C has at least the same sensitivity to decomposition as faster cycling organic C at the temperature and moisture conditions studied
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